求教prer07-cr2-48题~~~

hudongling001

48.(33231-!-item-!-188;#058&007563)

Certain messenger molecules fight damage to the lungs from noxious air by telling the muscle cells encircling the lungs' airways to contract.This partially seals off the lungs.An asthma attack occurs when the messenger molecules are activated unnecessarily, in response to harmless things like pollen or household dust.

Which of the following, if true, points to the most serious flaw of a plan to develop a medication that would prevent asthma attacks by blocking receipt of any messages sent by the messenger molecules referred to above?

(A) Researchers do not yet know how the body produces the messenger molecules that trigger asthma attacks.

(B) Researchers do not yet know what makes one person's messenger molecules more easily activated than another's.

(C) Such a medication would not become available for several years, because of long lead times in both development and manufacture.

(D) Such a medication would be unable to distinguish between messages triggered by pollen and household dust and messages triggered by noxious air.

(E) Such a medication would be a preventative only and would be unable to alleviate an asthma attack once it had started.

九段泡面高手

选D。题目：有一种msger可以在周围有毒气时让气管收缩来抵御毒气。有些人的机体无法分辨无害物质（如花粉，尘埃）和有毒气体，在不必要的时候让这种msger产生，这就是哮喘。

D：这种药无法分辨花粉刺激产生的msger和毒气刺激产生的msger。如果使用了这种阻止msger产生的药物的话，可能任何时候msger都会被阻止了，有毒气体来的的时候也会阻止（那就完了对吧）